Pump mechanism



Aug. 24, 1948. F. c. HAuMRsoN PUMP MECHANISM 3 Sheets-Sheet l Y Filed`ApIil 17, 1944 Nm. um wm. QQ v mwk WN.. Wm. ,4 N., m WW QN Byg] Y Haz/mensa. Mv/Maf, Y@

Aug- 24, 1948 F c. HAUMERSON i 2,447,650

PUMP MECHANISM Filed April 17,- 1944 s sheets-sheet 2 v ylvr/ENTO Wed' #annif-7430,7-

\1g,24, 1948. F, Q HAUMERSQN 2,447,650

PUMP MECHANISM Filed April 17, 1944 3 Sheets-Sheet 5 EJE.

IN V EN TUR. J /zumersprn /77 rok/vfys- Patented Aug. 24, 1948 STAT ES PATENT O'FLF'ICTJE .PUMP MnonAuIsM Fred' Haxnnersen, 'Racine Wis., assigner to Walker `Manufacturing Company lof Wisconsin,

Racine, Wis., a cor-poration of Wisconsin `Zipplicat'on April T7, 1944,.'Serial No. 531,332

(Cl. 10B-40) Z Claims. 1

The-present invention relates to pump mechanisms-well suited for, but notflimitedv to, use with Oras a 'part 'of hydraulicL jack assemblies.

The principal i obj ects Vof gthe present invention are ltoV provi-'de a pump mechanism embodying an improved arrangement lfor selectively renderling the successi-vegstrokes of a pump piston or equivalent 'l element effective and ineffective to transmit fluid from* a source oflluid to an associated' work chamber; to 4'provide such a structurewherei'n the justementioned arrangement mayv4 be caused lto operate automatically when the pressure in the' work chamber reaches apredetermined' value; to iinovide such a structure embodying an inlet check `valve between the source and `the pump, and further embodying means to control the position of such check valve so as to Aselectively render V'it eiective and ineiective to preventl a reverse ow from the pump to the source; to provide such a structure employing a plurality of simultaneously operable pump units. and embodying the aforesaid improvedarrangement for automatically placing oneior more of the pumpunits into or out of service; and to generally improve 4and lsimplify' the construction and arrangement of pump mechanisms of the above indicated type.

With the above as well' as other objects in view, which appear in the following description and in the appended' claims, a preferred but illustrative embodiment of the invention is shown in the accompanyingdrawings, throughout the several views of which corresponding reference characters are used to designate corresponding parts and in which:`

Figure 1 is a view in side elevation, partly in section, of" afloor'jack embodying thel invention;

Fi'g. '2- 'is a fragmentary view in longitudinal, vertical section of the structure shown in Fig. 1, taken `along the line 2-2` of Fig. 3i;

' Fig. sis a fragmentary-view .in -top plan fof the structureshownin Fig;V 1';

Eig; 4 isa viewin transverse, vertioalsection, taken` alongthe inet-4 oFFg. f3?

Fig. 5 .isa VView in transverse, vertical? section, taken alongY the lline 15-5 oi-` Fig; 13';-

Fig. 6. isvaviewL iin-transverse, vertical section, taken `along"the line f&- of Fig. 3;

Fig. "l is a. fragmentary View' in longitudirial..` vertical section, taken along the line T`1 of .8i .ra fragmentary/view in longitudinal.. vertical. section, taken along the line-88l of Eiga?.

It.: will `lief appreciated. from.: a. complete. under-:-

2 standing "of the present 'invention thatY the 4irnprovements thereof may be embodied in various different' forms and 'may vbe utilized for" various" different purposes; A 4preferred application of the invention is in connection 'with multiple pump units for hydraulic jacks audinjan illustrative, but not a 'limiting sense, the invention is so disclosed herein.

Referring first to 1, the illustrated iloor jack is one which embodies the invent-ion `dsclosed andV claimed' in. thev copending application of Raymond F. Manko, Serial No. 502,780, 4iled October 17, 1943. For the purposes. of the present description, it is suflicien'tto note that this floor jack` comprises` a longitudinally extending,

relatively low frame structure Il, Aprovf'icled with front and rear wheel assemblies l2 and i4, and also provided with a load engaginglifting cap l5. The .frame l0 accommodates a hydraulic ram and pump unit 1.8 which is pivotally supported, relative. `to the frarne by means o'f trunnions 20,. which project laterally from the rear end of the unit i8, and are rotatably receivedv in. bearings provided therefor Yin the frame structure.. 'The ram piston rod 2.4, which projects from` the front end of the unit. [8, carries a. 'head 26,. whichi-s coupled to theli'lting cap i6 through .a linkage which includes the. levers 28 `and 35. For the purpose of the present description, itis sulli cient.. to `note thatV .a projecting or rightwardi movement ofthe piston rod '24 causes. thefcap .ta to be elevated in a substantially linear vertical path. A retractingor leftward movement of` they piston rod 24 enables areturn of the cap IB .tothe illustrated position.. As` wil-l be understood, such retracting movement may be influenced.` by the load,l as. well as by a returnl spring 32., which is connected betweeny the head 26. and the yunit L8'.

Referring now particularly `to Figs. 2 through.

' 8, tl-ierarn and pumpuni-t t8 comprises a multipleV pump unit 40; anda.`cornbi:ned ram: and reservoir unit y42.. Unit 42:, which may be con.- ventional, comprises an outer, generally cylinJ drical .member 4.1, and an inner cylindrical membei'. v46.. The inner member 4.6 Vslidably receives a piston- 418, which is secured-to the previ-ouslyxmem. tion-edi pistonifrod 24,` and. is threaded into -a counterbore` provided inthe right-handy end sur-v face of the pump unit 40. The annular space 9% between members -44- and 46 constitutes a reserI voir for the operating, fluid, preferably" oil. It will vbe understood that a cap 5'0 (Fig. 1) forms. a

closure for the: right-hand end of the reservoir and that: such cap-is apertured to accommodate the vincrements .or the,` piston rod. 24. |The. left-- hand end of the outer member 44 is firmly seated upon an annular shoulder 52, provided in the corresponding end of the pump unit 40, all in accordance with conventional practice. In further accordance with conventional practice, oil may be introduced to the reservoir through a passage 54, one end of which opens directly into the reservoir space, and the other end of which may be closed by a plug 56.

In accordance with the broader aspects of the invention, the multiple pump unit 40 may be arranged to accommodate any desired number of pumps, three being shown by Way of illustration. The hereinafter described selecting mechanism is arranged to automatically respond to the magnitude of the load applied to the lifting cap 6, and to thereby either cause all three of the pumps, two of the pumps, or only one of the pumps to be effective to transmit fluid from the reservoir to the chamber space 58 behind the piston 48. It will be appreciated that by suitably proportioning the relative sizes of the several pumps, and the loadings at which such pumps are placed in or taken out of service, any desired ratios of handle effort and of lifting speeds can be afforded.

More particularly, the pump unit 40 is illustrated as comprising a unitary body, preferably a casting, which is provided with two laterally spaced, generally horizontally extending pump cylinders 60 and 62. The smaller cylinder 60 Vslidably receives a cylindrical piston 64, which is provided at its inner end with a usual packing element 66. The left-hand end of piston 64 projects outwardly of the pump body and is provided with a head 68, to which a pair of handle operated links 'l0 are pivotally connected. A packing gland 12 and a packing nut 14 serve to prevent leakage along the piston 64.

The larger cylinder 62 slidably receives a cylindrical member 16, which constitutes the piston of the largest or speed pump unit. Member 'I6 is provided with a bore 18, which slidably receives the cylindrical piston 80. Piston 80 is threadably secured in a counterbore 8| provided at the inner end of the cylindrical bore 62. Member 16 thus functions both as a piston and as a cylinder, the pump unit comprising member 'I6 and piston 80 being, in the present case, the so-called power pump, which remains continuously in service. The other two pumps, the cylinders for which are designated 60 and 62, are the intermediate and speed pumps, which are automatically placed in and taken out of service in the hereinafter described manner.

The outwardly projecting end 84 of member 16 is bifurcated, and is pivotally connected to a handle-operated link 86. Referring again to Fig. 1, links 10 and 86 are conventionally 'connected toausual ratchet type handle 88, reciprocating movements whereof serve to correspondingly and simultaneously reciprocate members 64 and 'I6 in their respective cylindrical bores.

Corning now to the fluid circuits through which the above-mentioned pumps serve to transfer uid from the annular reservoir 90 to the ram chamber 58, a pair of laterally displaced passages 92 and 94, tted with usual strainers 86, open, at their right-hand ends, into the reser- Voir 90, and open, at their other ends, into the diagonally extending header passage 98. Passage 98 is drilled in from one side of the pump body, and its outer end is closed by a usual plug |00. Adjacent the plugged end thereof, as shown in Figs. 2 and 5, passage 98 communicates with a vertically extending, stepped passage |02, the upper end whereof is closed by a removable plug |03. Passage |02 is provided with usual inlet and outlet ball type check valves |04 and |06, which are provided, respectively, with seats |06 and ||0. A usual spacer ||2 is slidably received in bore 02, between the just-mentioned check valves, andplug-I03 is provided with a usual post I4, which limits the upward movement of ball |06. Intermediate the seats |08 and ||0, passage |02 communicates with a longitudinally extending passage ||6, which opens into the counterbore 8| and which communicates through the axial passage ||8 in piston 80, with the previously-mentioned power pump chamber 18. Above the valve seat ||0, passage |02 communicates with a longitudinally extending passage |20, which opens directly into the ram chamber 58.

With the above described relation, it will be appreciated that a leftward or intake movement of member 16 enlarges chamber 18 and causes fluid to be drawn into header 98 through the passages 92 and 94. From header 98, the fluid flows past valve |04 and through passages |02, I6 and ||8 into chamber 18. Under these conditions, check valve |06 remains closed, eitherunder the influence of its own weight, or under the influence of any fluid pressure existing in the ram.

chamber 58. Duringv the succeeding rightward or discharge movement of pump member 16, on the other hand, the just-mentioned fluid is forced outwardly of chamber 18, through passages ||8 and 6 and thence through passage |02, past ball |06, and through passage |20 into the ram chamber 58. During this stroke, valve |04 is maintained on its seat under the influence of the fluid pressure in passage |02.

In accordance with usual practice, the power4 pump, comprising piston 80, is provided with a usual sprlng loaded relief valve |22, which is normally maintained on its seat |24 by means of the biasing spring |26. The chamber |28, associated with valve |22, communicates directly with the.

reservoir through passage |30 and communicates with passage |02 through a short vertical passage |32 and a plugged horizontally extend-l ing passage |34.

In addition and in accordance with usual practicey the present unit employs a conventional release valve |40, which may be turned from the illustrated closed position to an open position, by means of a usual remote connection |42, which may and preferably does extend to the hand grip of the jack handle 88, The previously mentioned relief passage |30 communicates with the chamber |44, associated with valve |40, through passage |4|. Chamber |44 also communicates with the ram chamber 58, through the previously mentioned passage |20. It will be understood that by opening valve |40, all fluid in the ram chamber 58 can be directly returned to the reservoir through the just-mentioned release circuit.

T-he reservoir passage 92 is drilled through and past the header 98 and its inner and reduced end portion |50 opens into a vertical passage |52, associated with the speed pump, the cylinder for which is designated 62. Passage |52 is provided with check valve seats |54 and |56, which accommodate the inlet and outlet ball check valves |58 and |60. Passage |52 is also provided with a usual spacer |62, and its upper end is closed by a plug |64. Between the valves |58 and |60, the vertical passage |52 communicates with a longitudinal passage |66, which opens into the inner enel of a lcylinder 62 within ythe annular space awr-nso.

the piston 80% the outlet cheek "valve in, passage- |52 intersects' a longittmnall passage 1'20, which opensA directly into theram chamber-50;

- As: far it will appreciated that a leftward or intake stroke of' member draws fluid from the header 90't i-r-xlto passage |152, pastzeheelcvalve |501 anni thrice-'through passage |66 intocyllinder 62. During, this stroke, valve W Iremains-clirrrsecl Einf-:ling vthe discharge or r-ifgiifisward vstrokeV or? member 16, the inst-mentioned Huid''s toxceiilv outwardly through passage $66,. passage F52, past'. valve |601, and thence passage 12E-into the `rantv chamber 58". Bunting-Imis stroke, valve v|550 nonnallyf remains cikasedf under the .in-iluenc'ev of Ythe fluid pressure iine 52..

In accordance withthe present invention, the pmnp unit`` comprising member 16: and cylinder 62 is automatcaliy taken out of service when thepressureinthe ram-chamber 58 is at lor above a predetermined' value, by means which maintan- `the inlet' check valvel |58 oi'f its seat. As illustrated, (Fig: 4o! this is accomplishedlby proviciing a spring-ltiased operating post |10, which is slidably received in a short bore |12, which openstntothepassage 7F52; in the vicinity of valve |58. Post |10 is normally held inthe illustrated retracted position, by meansof a compression f placevabyrv a packing nut In, and projects-into aA chamber |114.. The outer end of chamber ttzis -closed by aremovable plug |86 andths chamber communicates, througna, pluggeety vertical passage |88, with thee longitudinal. .passage |200;4 which. opens directly intof the. ram chamber 56.. Pressure withinchamber |04::and which :acts againstthe outer end. ofpost: |210; is thusl at Vall times esula-Lto the ,pressure within the ram-chamber; Snel-r pressure. opposes spring |14,.'it being understood that so long as iluid, pressureapplied toipcst' |101isbelow a predetermined value,spring ffl-'4` is Veifective to maintain post |10 in; its left.- hand or retracted position.. In such retracted position, pest |10 does notv intereiere withthe normal opening. and closing. movements of valve |58.

Assuming now that thev load-against which the jack; is actingv is. .suiciently high to establish a fluid pressure in the ram chamber 53 which overcomes the biasing effect of spring |14, post |10 is actuated to its projected position in which it prevents a reclosing movement of valve |58. More particularly, it may be assumed that such superior ram pressure is attained during a discharge stroke of the pumping mechanism. During such discharge stroke, the pressure in chamber |84 is substantially equal to the pressure in chamber |52. The latter pressure acts with the spring |14 and post |10 thus remains in its retracted position until the end of the discharge stroke in question. At the beginning of the succeeding intake stroke, on the other hand, the pressure in passage |52, below valve |60, falls to a very low value. Under these conditions, the fluid pressure applied to post |10, through chamber |84, is opposed only by spring |14 and, under the conditions stated, is eli'ective to move post |10 to the right, as viewed in Fig. 4. Since an intake stroke is now in progress, valve |58 may be regarded as already off its seat, and the rightward movement of post |10 thus serves to force valve |58 to the right-hand side ofi passage |52", in which the underside oli-valve F58 rests'upon of' itsaseat: |156. At the conclusion oiiA the intake stroke question, fluid' is forcedf out off-cylinder E2' through |266; and the resultant fluid' pressuren the-lowerpart: of passage ltends to reseat valve=i|50 the elevated position iin valve I'Fis now heldby post' |10; however, a substantialfiy free and' 'unobstructed' return passage tothe reservoir; through passage f| 50 and; header 58, is afforded. Thefjlust-mentoned seating `pres-- acting'against val-wie |58 is: thus very low and is ineilective` to returnA the val-ve to the closed sition; Sof lion-'g as the ram load remains above the above-mentioned predetermined value, thereiere, inlet: valve 58 eontinuouslyl remains in the open pos'irtion.. Accordingly', ltil-e intake andydischarge strokes ol" the speed? pumpI serve only te draw nuidfrom the reservoir into cylinderwand return such iiluid. directly to the reservoir through therinlet circuit. Substantially no. handle effort, isutilizedinfproducing the just-men-tonedfI transff-er et fluid. Y

lte-i'errirxgV now' to the fluid lcircuits associated with the intermediate pump unit. 'tie-s60, hea-der ilkfcommun-icates immediately' adacent `its inner end with fa. vertical :passage 200, which 'isv proruided wtthrinletzand 4@itischargeball valves. 202 and 2M. 'Passage 200* 'is also. provided: witihV a usual spacer V2065, and: a clfosure'plug Between the. and outlet check val-ves 2112* `and 1R01;l passage 2100 communicates.: with a` longitudinali passage. 23M, which opens into inner end of cylinder 60. The inlet `circuit for the inter'- mediate .pump unit '6 0,-64 thus extends: from the header 585,. through: passage i200, past, the. inlet vatte 202, andl through .the passage 210! into. cyl-- inder 6D. 'The dischargewcirouit for thisV puin-pY entendsl fzromfcylinder E0, through` passage 2111), thefupperporton oi passage 2.0.0, .past check valve. 20.4., und; through. passage Ai 00 (which passes through passage 200).., into the ram 'chamber' 53.. It willEM bev -moderstoodfthatthe normali operat'rocr of'thiszpumpfis thefsame asthat of the other pumps.,

2in-further accordance with the present: inventiem. the; intermediate pump Sil-6e is 'zprovideclf with control means. 4'similar tot'hat .described 'in connection with. the Vspeed .porn-p.` More particularlygga controll post 220* sliclably received bore which opens into 'the' passage Millv in the: region `of.y valve- 210.2. Post 220- biased to :its retracted` positiomiby a compression .spring 222:, which is seated between the end of the counterbore 224 and a collar 226 xed on post 220. Post 220 extends through a packing gland 228 and a packing nut 230 into a small chamber 240. Chamber 240 communicates, through a plugged vertical passage 242, provided with a plug 244, with the previously mentioned longitudinal passage |20, which opens directly into the ram chamber 58.

As in the case of the speed pump, post 220 is held retracted, so long as the pressure in the ram chamber is below a predetermined value. During the course of the rst intake stroke of pump 60-64, which follows a rise in the pressure in the ram chamber above such value, however, post 220 is quickly moved to its projected position, in which it is effective to hold valve 202 in the open position. So long as the ram pressure is above this set value, valve 202 remains open, and the intake and discharge strokes of piston 64 serve only to draw uid from the reservoir and return it thereto through the inlet circuit.

As mentioned above, the pressure values at which the respective speed andV intermediate pumps are taken out of service may be varied widely to suit different operating conditions. As an example, the pressuresettings may be such that when the floor jack is unloaded, as when the lifting cap is being elevated into initial ensagement with the load, all three pumps are in service. Each handle stroke thus produces a lifting movement determined by the combined displacements of all three pumps, producing a 'relativelyrapid travel. The vinitial engagement of the lifting cap with the load, of course, immediately increases the pressure in the ram chamber to a substantial value, and normally the control setting for the speed pump is such that for intermediate loads the speed pump is taken out of .service at the time of such engagement. For certain types of such intermediate loads, the resistance to lifting motion may not be substantially increased during the continued travel of the jack. In such cases, the power and intermediate pumps may remain effective throughout the balance of the lifting movement, affording an intermediate lifting rate without requiring an undue handle effort.

In cases where the load is well above an intermediate value, it is desirable to effect the lifting movement by the use of only the power pump. Accordingly, the control setting for the intermediate pump' 60-64 is set at a value considerably abovefthe controlsetting for the speed pump. If and when the load reaches a value corresponding to such higher setting, the intermediate pump is taken out of service. As will 4be understood, this higher load value may be reached, in certain cases, at the time the load is initially engaged and may be attained, in other cases, during the course of the lifting movement.

The power pump remains continuously in service, as aforesaid, a limit to the force which may be applied to the load therethrough being afforded by the relief valve |22.

To lower the load, as aforesaid, the release valve |40 may be turned to the open position, affording a direct exhaust circuit from chamber 58 to thereservoir. W'hen, during the course of the consequent lowering movement of the jack, the load falls below the respective control settings of the speed and intermediate pumps, the springs |14 and 222 associated therewith become effective to retract their control posts |10 and '220, thereby restoring the corresponding inlet valves to their normally effective conditions.

Although only a single specific embodiment of the invention has been described in detail, it Will be appreciated that various modifications -in the form, number and arrangement of parts may be made without departing from the spirit and scope of the invention. l

What is claimed is:

1. In a Dumping mechanism for transferring fluid from a first space to a second space, pump*- ing means for effecting said transfer, means including a passage between said spaces through which fluid is caused to flow by said pumping means, spaced inlet andv outlet valve seats in said passage and valves therefor, means defining a passage opening into said first-mentioned pas' sage between said seats, and a ycontrol member movable through said second-mentioned passage into said first-mentioned passage and'engageable with said inlet valve for controlling the position of said inlet valve relative to its seat.

2. The structure of claim 1 wherein said control member is operably responsive to the pressure in said second 4space and is effective when said pressure in said second space Vattains a predetermined value to hold said inlet valve off its seat.

FRED C. HAUMERSON.

REFERENCES CITED The following references are of record in 'the file of this patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Number Number Date Germany 1931 

